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Data Management System for Data Base Conversion

IP.com Disclosure Number: IPCOM000078476D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 48K

Publishing Venue

IBM

Related People

Philibert, JP: AUTHOR

Abstract

This method enables the concurrent access to a data set by emulated programs and programs running under the Operating System in use, the data set being controlled by the new Operating System building and accessing procedures. This result is obtained by: 1) the addition of one or several "intermediate data set(s)" to a data set converted to the new operating system; it contains the physical data which existed on the physical volume where the data set resided and 2) a Channel Program Interpreter (complete or partial) used for determining the aim of a channel program.

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Data Management System for Data Base Conversion

This method enables the concurrent access to a data set by emulated programs and programs running under the Operating System in use, the data set being controlled by the new Operating System building and accessing procedures. This result is obtained by: 1) the addition of one or several "intermediate data set(s)" to a data set converted to the new operating system; it contains the physical data which existed on the physical volume where the data set resided and 2) a Channel Program Interpreter (complete or partial) used for determining the aim of a channel program.

One of the most critical problems of user conversion from an "old system" to a "new system" is concerned with Data Conversion. Up to now, two methods have been used:

1. Physical simulation: The old volumes are stored in the format of the new system in such a way, that each physical track with its old structure (including, besides data, identification information like count, key det. ..) is mapped into a record of the new system. During the emulation of an old program, when a request for an input-output operation against a volume (or a data set) is intercepted, the channel program is simulated command by command. This method does not allow data sharing, but it allows the emulation of all programs.

2. Logical simulation: The data set's logical structure is converted in accordance with the requirements of the new system and stored in the format of the new system. During the emulation of an old program, the emulator intercepts the request for a data-set access, analyses it, converts it into the corresponding request for the new system and issues it against the converted data set. This method allows the sharing of data sets between old programs and new programs, but is subject to restrictions because the interpretation of the requests is not always possible.

The proposed me...